Indoor unit, air conditioner including indoor unit and method of controlling air conditioner

ABSTRACT

An in-ceiling embedded type air conditioner including an indoor unit having an air blower and an indoor heat exchanger accommodated in a housing a substantially box-shape, and a filtering unit including a gas-liquid contact member that is disposed at the downstream side of the indoor heat exchanger on an air blowing passage through which air sucked by the air blower flows in the indoor unit and in filtrated with electrolytic water generated by electrolyzing water, the air and the electrolytic water being brought into contact with each other in the gas-liquid contact member, whereby the air cooled or heated in the indoor heat exchanger is filtered, that is, virus, etc. contained in the air is inactivated, sterilized or the like and then blown out to a room to be air-conditioned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an indoor unit, an air conditionerhaving the indoor unit and a method of controlling the air conditioner.

2. Description of the Related Art

Microorganism such as bacteria, virus, fungus, etc. (hereinafterreferred to as ”virus, etc.”) float in indoor air, and thus air blownout from an air conditioner also unexceptionally contains virus, etc. Ifthe virus, etc. contained in indoor air are inactivated, sterilized,decomposed, removed or the like (hereinafter referred to as ”filtered”)and then the filtered air is blown out from the air conditioner into theroom, it is expected to have an effect of lowering the risk ofinfection, induction of allergy, adverse effect, etc. to people withweak defense power or even general people in congested areas, and it canbe practically used.

In view of this problem, there is known an air cleaning technique for anair conditioner to which an air cleaner for oxidizing, decomposing andremoving harmful materials from air is connected. According to thismethod, air is once sucked from a room and filtered to oxidize,decompose and remove harmful materials from the air, and then returnedto the air conditioner. The filtered air is air-conditioned in the airconditioner and then clean air is blown out to the room (for example,JP-A-2003-250876).

In this air cleaning technique, however, the air cleaner is assembledand installed separately from the air conditioner, and they areconnected to each other through air flowing pipes. Accordingly, theoverall construction of the air conditioner and the air cleaner areexcessively large, that is, this technique requires a large installationspace. Furthermore, the air conditioner and the air cleaner must bemanufactured and fabricated separately from each other, and thus thetotal number of parts constituting the air conditioner and the aircleaner must be increased, so that the manufacturing cost thereof isincreased. In addition, with respect to the maintenance of the airconditioner and the air cleaner, they must be separately subjected tomaintenance and check works. Therefore, the maintenance and check worksare cumbersome.

SUMMARY OF THE INVENTION

The present invention has been implemented in view of the foregoingproblems, and has an object to provide an air conditioner having airfiltering capability such as inactivation, sterilization, decomposition,etc. of virus, etc. floating in the air.

Furthermore, the present invention has an object to provide an airconditioner having air filtering capability in which an air conditioningoperation and an air filtering operation can be freely and selectivelyperformed with a simple operation, and a method of controlling the airconditioner concerned.

In order to attain the above objects, according to a first aspect of thepresent invention, an indoor unit of an in-ceiling embedded type airconditioner including an air blower and an indoor heat exchangeraccommodated in a housing a substantially box-shape, comprises: afiltering unit including a gas-liquid contact member that is disposed atthe downstream side of the indoor heat exchanger on an air blowingpassage through which air sucked by the air blower flows in the indoorunit and infiltrated with electrolytic water generated by electrolyzingwater, the air and the electrolytic water being brought into contactwith each other in the gas-liquid contact member to filter the air.

According to the above indoor unit, the air passing through the indoorheat exchanger is passed through the gas-liquid contact member filtratedwith electrolytic water, whereby the air is filtered. Therefore, virus,etc. contained in the air whose temperature is adjusted by cooling orheating can be inactivated or removed. Accordingly, the air conditionercan be brought with the air filtering function. Furthermore, the indoorunit of the in-ceiling embedded air conditioner suffers no restrictionof the installation space on the floor surface of the room to beair-conditioned. Therefore, the user can keep the indoor air clean whileavoided from being loaded to secure the installation space.

In the above indoor unit, it is preferable that the housing has anopening portion at at least a part of the side surface thereof and thegas-liquid contact member is inserted from the opening portion into thehousing.

In this case, the opening portion is provided in the side surface of thehousing of the indoor unit, and thus the gas-liquid contact member canbe easily secured to the indoor unit by inserting the gas-liquid contactmember through the opening portion.

In the above indoor unit, it is preferable that the filtering unitfurther comprises a plate-shaped member covering the opening portion,and an electrolytic bath for generating the electrolytic water, and theelectrolytic bath is fixed to one surface of the plate-shaped member,and the gas-liquid contact member is fixed to the other surface of theplate-shaped member.

According to the above construction, the plate-shaped member is fixed tothe housing and the gas-liquid contact member and the electrolytic bathare simultaneously fixed to the plate-shaped member, whereby thegas-liquid contact member and the electrolytic bath can be easilysecured to the indoor unit. Furthermore, the gas-liquid contact memberand the electrolytic bath are proximate to each other, and thus theelectrolytic water generated in the electrolytic bath can be quicklysupplied to the gas-liquid contact member.

In the above indoor unit, it is preferable that the filtering unitfurther comprises a water supply pipe that is disposed along arefrigerant pipe connected to the indoor heat exchanger and supplieswater to the electrolytic bath.

In this case, when the indoor unit is embedded in the ceiling, aconnection work of the water supply pipe and the refrigerant pipe can becollectively performed, and thus the installation work can besimplified.

In the above indoor unit, it is preferable that the filtering unitfurther comprises an electrolytic bath that is disposed at the outsideof the housing and generates the electrolytic water.

According to this construction, the electrolytic water is generated bythe electrolytic bath which is located outside the housing, and thus theelectrolytic bath does not disturb flow of air in the housing of theindoor unit and also does not narrow the air flow passage. Therefore,unfavorable matters such as increase of the air flowing resistance, etc.are not induced, and the space in the housing can be effectively used.Furthermore, the maintenance of the electrolytic bath can be simplyperformed from the outside of the housing of the air conditioner.

In the above indoor unit, it is preferable that the filtering unitfurther comprises a water supply pipe that is disposed along arefrigerant pipe connected to the indoor heat exchanger and supplieswater to the electrolytic bath.

In this case, when the indoor unit is embedded in the ceiling, aconnection work of the water supply pipe and the refrigerant pipe can becollectively performed, and thus the installation work can besimplified.

In the above indoor unit, it is preferable that the filtering unitcomprises a drain pan that is disposed below the indoor heat exchangerand receives drain water from the indoor heat exchanger, a drain pumpfor discharging drain water from the drain pan, an electrolytic watersupply unit for supplying the electrolytic water to the gas-liquidcontact member from the upper side thereof so that the electrolyticwater infiltrates the gas-liquid contact member, an electrolytic watertray that is disposed below the gas-liquid contact member and receiveselectrolytic water dropped from the gas-liquid contact member, and adischarge pipe for discharging electrolytic water stocked in theelectrolytic water tray to the drain pan.

According to this construction, the electrolytic water supplied to thegas-liquid contact member is dropped from the gas-liquid contact memberand discharged to the drain pan. Therefore, the electrolytic water canbe easily discharged together with the drain water. Furthermore, theelectrolytic water having sterilization power flows in the drain pan,and thus breeding of various bacteria, etc. in the drain pan can besuppressed. Still furthermore, the electrolytic water dropped to thegas-liquid contact member is temporarily stocked in the electrolyticwater tray and then flows to the drain pan. Therefore, the discharge ofthe electrolytic water from the electrolytic water tray to the drain pancan be controlled by opening/closing the discharge pipe. Accordingly,for example, the electrolytic water in the electrolytic water tray isnot discharge, but circulated and re-used, so that the electrolyticwater can be efficiently used.

In the above indoor unit, it is preferable that the drain pump isdisposed at one corner of the housing, and the gas-liquid contact memberis disposed along the side surface of the housing so as to be adjacentto the locating position of the drain pump.

According to this construction, the gas-liquid contact member and theelectrolytic water tray are located in the neighborhood of the drainpump. Therefore, the electrolytic water discharged to the drain panquickly reaches the drain pump, and also is quickly discharged by thedrain pump. Accordingly, the electrolytic water does not stay in thedrain pan for a long time, and thus the effect of the electrolytic wateron the indoor heat exchanger can be minimized. Therefore, for example,when an anticorrosive treatment is conducted on the indoor heatexchanger, the treatment area can be minimized.

In the above indoor unit, it is preferable that the filtering unitfurther comprises a circulating and supplying unit for circulating andsupplying electrolytic water stocked in the electrolytic water tray tothe gas-liquid contact member.

According to the above construction, the electrolytic water can becirculated and efficiently used, so that the user amount of water can besuppressed.

According to a second aspect of the present invention, an airconditioner including an outdoor unit having a compressor and an outdoorheat exchanger, and an indoor unit having an air blower and an indoorheat exchanger, the outdoor unit and the indoor unit being connected toeach other through a joint pipe, comprises: an air filtering apparatusincluding a gas-liquid contact member that is disposed on an air flowingpassage formed by the air blower of the indoor unit and infiltrated withelectrolytic water containing active oxygen species so that air passingthrough the gas-liquid contact member is brought into contact with theelectrolytic water to filter the air; and a controller for controllingthe air conditioner having the air filtering apparatus, and selectivelyexecuting, as an operation mode, an interlocking operation mode forinterlocking an air-conditioning operation based on the air conditionerand an air filtering operation based on the air filtering apparatus, andan independent air filtering operation mode for executing only the airfiltering operation based on the air filtering apparatus withoutexecuting the air-conditioning operation based on the air conditioner.

According to the above air conditioner, the interlocking operation modeand the operation stop mode can be executed under the control of thecontroller. When the interlocking operation mode is executed, the indoorair executes the air conditioning operation of the room, and alsoexecutes the air filtering operation. Accordingly, the air filteringoperation can be executed interlockingly with the air-conditioningoperation, or the air filtering operation can be stopped interlockinglywith the stop of the air-conditioning operation. Furthermore, when theindependent air filtering operation mode is executed, only the airfiltering operation can be executed. Accordingly, the interlockingoperation mode in which the air-conditioning operation and the airfiltering operation are interlocked with each other and the independentair filtering operation mode in which only the air filtering operationis executed can be easily switched therebetween and executed.

It is preferable that the above air conditioner further comprises aswitching operation unit for instructing switching of the operationmode. Furthermore, according to an instruction from the switchingoperation unit, the controller shifts the operation mode to anyone modeof an independent air-conditioning mode for stopping the air filteringoperation based on the air filtering apparatus during execution of theinterlocking operation mode and executing the air-conditioningoperation, and the interlocking operation mode for starting the airfiltering operation based on the air filtering apparatus duringexecution of the independent air-conditioning mode and executing boththe air-conditioning operation and the air filtering operation.

In this case, by user's operation of the switching operation unit, theoperation mode can be shifted to the independent air-conditioningoperation mode of stopping the air filtering operation during executingof the interlocking operation mode and executing the air-conditioningoperation, and also the operation mode can be shifted to theinterlocking operation mode in which the air filtering operation basedon the air filtering apparatus is started during execution of theindependent air-conditioning operation mode. Accordingly, the operationmodes achieved by combining the air-conditioning operation and the airfiltering operation can be switched and executed.

In the above air conditioner, it is preferable that the controllercontrols the indoor unit to execute air blowing operation based on theair blower in the independent air filtering mode.

In this case, by driving the air blower for air-conditioning operationunder the state that only the air filtering apparatus is operated, thefiltered air can be supplied to the room without providing any airblower dedicated to the air filtering apparatus.

According to a third aspect of the present invention, a method ofcontrolling an air conditioner including an outdoor unit having acompressor and an outdoor heat exchanger, an indoor unit having an airblower and an indoor heat exchanger, and an air filtering apparatusincluding a gas-liquid contact member that is disposed on an air flowingpassage formed by the air blower of the indoor unit and infiltrated withelectrolytic water containing active oxygen species so that air passingthrough the gas-liquid contact member is brought into contact with theelectrolytic water to filter the air, the air conditioner having the airfiltering apparatus being operated in each of operation modes includingan interlocking operation mode for interlocking an air-conditioningoperation based on the air conditioner and an air filtering operationbased on the air filtering apparatus, and an independent air filteringoperation mode for executing only the air filtering operation based onthe air filtering apparatus without executing the air-conditioningoperation based on the air conditioner, comprises: a step of detectingan instruction of starting the air-conditioning operation or the airfiltering operation; a step of judging whether the air conditioner isnow under operation or under non-operation; and a step of starting theinterlocking operation mode when an instruction of starting theair-conditioning operation is detected and it is also judged that theair conditioner is now under non-operation, and starting the independentair filtering operation mode when an instruction of starting the airfiltering operation is detected and the air conditioner is now undernon-operation.

According to the above air conditioner and the above method, theinterlocking operation mode of interlocking the air-conditioningoperation and the air filtering operation based on the air filteringapparatus, and the independent air filtering operation mode of executingonly the air filtering operation based on the air filtering apparatusare provided, and various operation states in which only the airfiltering operation is executed, both the air-conditioning operation andthe air filtering operation are executed/stopped interlockingly witheach other, etc. can be switched to one another by a simple operation,so that the operationality can be enhanced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing the construction of an air conditionerequipped with an air filtering apparatus according to a first embodimentof the present invention;

FIG. 2 is a cross-sectional view showing the construction of an indoorunit of the air conditioner in which the air filtering apparatus isequipped;

FIG. 3 is an exploded perspective view of the indoor unit having the airfiltering apparatus shown in FIG. 1;

FIG. 4A and 4B are diagrams showing the construction of the main part ofan filtering unit of the air filtering apparatus, wherein FIG. 4A showsan air filtering portion, and FIG. 4B shows an electrolytic water supplyunit;

FIG. 5 is a systematic diagram showing the flow of electrolytic waterpassing through the air filtering portion of FIG. 4A;

FIG. 6 is an exploded perspective view showing an indoor unit having anair filtering apparatus according to a second embodiment;

FIG. 7 is a cross-sectional view showing an indoor unit having an airfiltering apparatus according to a third embodiment of the presentinvention;

FIG. 8 is a block diagram showing an air filtering apparatus accordingto a fourth embodiment;

FIG. 9 is a state transition diagram showing transition of an operationmode of the air filtering apparatus shown in FIG. 8; and

FIG. 10 is a flowchart showing the operation of the air filteringapparatus shown in FIG. 8.

PREFERRED EMBODIMENTS OF THE PRESENT INVENTION

Preferred embodiments according to the present invention will bedescribed hereunder with reference to the accompanying drawings.

In the following embodiments, a four-way blow-out and in-ceilingembedded type air conditioner will be described as an example of an airconditioner according to the present invention. However, the type of theair conditioner is not limited to the above type, and various types ofair conditioners such as a ceiling-suspended type air conditioner, awall-suspended type air conditioner, an on-floor mount type airconditioner, etc. may be adopted.

First Embodiment

FIG. 1 shows the construction of an air conditioner 100 according to afirst embodiment of the present invention. The air conditioner 100according to the first embodiment is a separation type heat pump airconditioner having an outdoor unit 1 and an indoor unit 2. An outdoorrefrigerant pipe 10 of the outdoor unit 1 and an indoor refrigerant pipe34 of the indoor unit 2 are connected to each other through a connectionpipe 35, and the outdoor unit 1 and the indoor unit 2 are controlled bya controller 8.

The outdoor unit 1 is installed outdoors. As shown in FIG. 1, acompressor 11 is disposed in the outdoor refrigerant pipe 10, anaccumulator 12 is connected to the suction side of the compressor 11,and a four-way valve 13, an outdoor heat exchanger 14 and anelectrically-driven expansion valve 15 are successively connected to thedischarge side of the compressor 11 in this order. Furthermore, anoutdoor fan 16 for blowing air to the outdoor heat exchanger 14 isdisposed in the outdoor unit 1.

The indoor unit 2 is installed in a room to be air-conditioned. As shownin FIG. 1, the indoor unit 2 includes a housing having an air suctionport 31 and an air blow-out port 32, an indoor heat exchanger 21, an airblowing fan (air blower) 22 for making air flow from the air suctionport 31 to the air blow-out port 32, and an air filtering unit 4 whichis disposed in an air flowing passage formed in the housing 20 by theair blowing fan 22 and brings air heat-exchanged in the indoor heatexchanger 21 into contact with electrolytic water containing activeoxygen species to filter the air.

The controller 8 is equipped with CPU (not shown), ROM for storing acontrol program executed by CPU, control data associated with thecontrol program, etc., and RAM for temporarily storing programs executedby CPU and various kinds of data. The controller further has an infraredreceiver for receiving an infrared signal transmitted from a remotecontroller (not shown) out of the indoor unit 2. CPU receives aninstruction from the remote controller on the basis of the infraredsignal received by the infrared receivers, reads out the control programstored in ROM according to this instruction, develops the controlprogram in RAM and executes the control program, thereby controlling theoverall air conditioner 100.

In the air conditioner 100, the flow direction of refrigerant flowing inthe refrigerant circuit 100 a is switched by switching the four-wayvalve 13, whereby a cooling operation and a heating operation areswitched therebetween. Under cooling operation, the refrigerant flows ina direction indicated by a solid-line arrow shown in FIG. 1, and underheating operation, the refrigerant flows in a direction indicated by abroken-line arrow in FIG. 1.

That is, under cooling operation, high-pressure refrigerant dischargedfrom the compressor 11 passes through the accumulator 12 and reaches theoutdoor heat exchanger 14. The refrigerant concerned is condensed in theoutdoor heat exchanger 14, and fed to the electrically-driven expansionvalve 15. This high-pressure refrigerant is passed through theelectrically-driven expansion valve 15 while expanding, evaporated inthe indoor heat exchanger 21 and then returned to the suction side ofthe compressor 11. Under heating operation, the high-pressurerefrigerant discharged from the compressor 11 is passed through theoutdoor refrigerant pipe 10, fed to the indoor heat exchanger 21,condensed in the indoor heat exchanger 21 and then fed to theelectrically-driven expansion valve 15. This refrigerant expands in theelectrically-driven expansion valve 15, and it is fed to the outdoorheat exchanger 14, evaporated in the outdoor heat exchanger 14, fedthrough the four-way valve 13 to the accumulator 12 and then returned tothe suction side of the compressor 11.

FIG. 2 is a side cross-sectional view showing a state that the indoorunit of the air conditioner according to the first embodiment of thepresent invention is embedded in the ceiling. FIG. 3 is an explodedperspective view showing the state that the indoor unit 2 shown in FIG.2 is exploded while the upper and lower sides thereof are inverted.

The indoor unit 2 has a housing 20 in which the indoor heat exchanger21, the controller 8, etc. are accommodated, and a face panel 30 issecured to the front side (room side) of the housing 20. As shown inFIG. 2, the face panel 30 is located at the lower side of the housing 2under the state that the indoor unit 2 is secured to the ceiling asshown in FIG. 2.

The housing 20 is designed in a substantially rectangular box-shapehaving an opened front face (the lower-side face of the housing 20 inFIG. 2 or the upper-side face of the housing 20 in FIG. 3).

The side surface of the housing 20 is constructed by joining threesubstantially rectangular side plates 20 a and one substantiallyrectangular side plate 20 e. Another flat plate is interposed at eachjoint portion of the respective side plates, and these side platesconstitute a substantially octagonal frame as a whole.

A knock-out hole portion 20 c is formed at each side plate 20 a. Theknock-out hole portion 20 c is a substantially rectangular hole coveredby one plate constituting the side plate 20 a. By pushing the knock-outhole portion 20 c as occasion demands, the plate covering the hole dropsoff and thus the knock-out portion 20 c is opened. The opening formed bypushing the knock-out hole portion 20 c is referred to as an openingportion 20 d.

A cut-out portion 20 f is formed at one end side of the side plate 20 eso as to guide the indoor refrigerant pipe 34, etc. connected to theindoor heat exchanger 21 in the indoor unit 2.

The face panel 30 is substantially rectangular in plan view, and morespecifically it is formed in a substantially square shape. The openingface of the housing 20 and the ceiling hole 102 are covered by the facepanel. The face panel 30 is provided with an air suction port 31 locatedat the substantially center portion in plan view and air blow-out ports32 which are disposed in the neighborhood of the four sides of the facepanel 30 so as to extend along the four sides. The air blow-out ports 32extend substantially in parallel to the side plates 20 a, 20 e, and itis configured so that air passing through the indoor heat exchanger 21described later can be efficiently discharged to a room to beair-conditioned.

Furthermore, a filter 33 is mounted inside the air suction port 31, thatis, at the back side of the ceiling 101. Accordingly, the indoor unit 2sucks indoor air from the air suction port into the housing 20,heat-exchanges the air in the housing 20 and then blows out theheat-exchanged air in the four directions from the four air blow-outports 32 into the room to be air-conditioned.

Suspending tags 103 are secured to the four corners of the housing 20.As shown in FIG. 2, the indoor unit 2 is embedded in the direction fromthe room to the back side of the ceiling 101 into the ceiling hole 102formed in a substantially rectangular shape of the ceiling 101 of abuilding in which the indoor unit 1 is installed, and suspended in theceiling space by fixing the suspending tags 103 to suspending boltssuspended from the back side of the ceiling.

Next, the internal construction of the housing 20 will be described withreference to FIGS. 1 to 3.

As shown in FIG. 2, a thermal insulating member 20 formed of foamedpolystyrene is provided to the inner surface of the side plates 20 a ofthe housing 20. A motor 22 a is fixed to the inside of the top plate 20b of the housing 20, and a vane wheel 22 b is secured to the shaft ofthe motor 22 a. These elements constitute the air blowing fan 22. Theindoor heat exchanger 21 which is bent in a substantially rectangularshape along the side plates 20 a and 20 e of the housing 20 is disposedinside the thermal insulating member 23 formed of foamed polystyrene soas to surround the air blowing fan 22 (see FIG. 3). Air is supplied fromthe air suction port 31 to the indoor heat exchanger 21 by the airblowing fan 22, and the air heat-exchanged in the indoor heat exchanger21 is blown out from each air blow-out port 32.

As described above, the indoor heat exchanger 21 disposed in the housing20 has the shape along the substantially octagonal frame constructed bythe side plates, and the faces of the indoor heat exchanger 21 whichface the side plates 20 a, 20 e are flat. A drain pan 24 of foamedpolystyrene is disposed so as to be spaced from the edge of the indoorheat exchanger 21 at a predetermined distance. The outer periphery ofthe drain pan 24 is substantially in contact with the inner surface ofthe housing 20. The drain pan 24 is located below the indoor heatexchanger 21 under the installation state of the indoor unit 2 shown inFIG. 2, and it receives and stocks dew condensation water (drain water)dropped from the indoor heat exchanger 21 mainly under coolingoperation. A drain pump 27 is disposed at the position corresponding toone corner of the indoor heat exchanger 21, and the drain water stockedin the drain pan 24 is pumped up by the drain pump 27. The drain waterpumped up by the drain pump 27 is discharged to the outside of theindoor unit 2 by a drain pipe 27 a passing through the cut-out portion20 f and extending to the outside of the housing 20. A joint pipe(refrigerant pipe) 35 (FIG. 1) extending from the indoor heat exchanger21 is passed through the cut-out portion 27 f (FIG. 1).

An air suction opening 25 and air blow-out openings 26 are provided atthe positions corresponding to the air suction port 31 and the airblow-out ports 32 of the face panel 30. As shown in FIG. 3, the airsuction opening 25 is formed in a substantially circular shape in planview at the center of the substantially rectangular drain pan 24.Furthermore, the air blow-out openings 26 are formed along the foursides of the drain pan 24. The air blow-out openings 26 of the drain pan24 are located at the positions corresponding to the flat portion of theindoor heat exchanger 21, and air is passed from the air blow-outopenings 26 through the air blow-out ports 32 and blown out into theroom to be air-conditioned.

Furthermore, a filtering unit 3 to which an air filtering unit 4, etc.are secured is inserted from the outside into the opening portion 20 dformed at the knock-out hole portion 20 c. In the air conditioner 100according to the first embodiment, the knock-out hole portion 20 c isopened in one side plate 20 a adjacent to the one corner at which thedrain pump 27 is disposed, out of the three side plates 20 aconstituting the housing 20 of the indoor unit 2, and the filtering unit3 is disposed there.

The filtering unit 3 is equipped with a base plate (plate-like member) 3a which closes the opening portion 20 d, the filtering unit 3 isinserted into the opening portion 20 d, and the base plate 3 a and theside plate 20 a are fixed to each other, whereby the opening portion 20d is closed.

The air filtering unit 4 is secured to the base plate 3 a before it isinserted into the housing 20. The air filtering unit 4 is supported 3 aby fixing tags 61 so as to be spaced from the base plate 3 a at apredetermined interval, and a thermal insulating member of foamedpolystyrene is provided between the base plate 3 a and the air filteringunit 4.

An electrolytic water supply unit 5, a water control valve 46, a checkvalve 47, a circulating pump 49, an electrical component board 40, etc.are secured to the outer surface of the base plate 3 a at the outside ofthe housing 20.

The filtering unit 3 has a substantially box-shaped exterior cover 80which covers the housing 20 from the outside. This exterior cover 80 isjoined to the outside of the housing 20, and it accommodates therespective parts of the filtering unit 3 such as the electrolytic watersupply unit 5, the water (tap water or the like) control valve 46, thecheck valve 47, the circulating pump 49 and the electrical componentboard 40.

Under the state that the filtering unit 3 is inserted and fitted in theopening portion 20 d, the air filtering unit 4 is located so as to beadjacent to the indoor heat exchanger 21. The air filtering unit 4 islocated at the outside of the indoor heat exchanger 21, so that airblown by the air blowing fan 22 and passing through the indoor heatexchanger 21 is blown to the air filtering unit 4. This air passesthrough the air filtering unit 4 while filtered (i.e., the virus, etc.contained in the air are inactivated, sterilized, decomposed or thelike), flows downwardly in the space between the air filtering unit 4and the base plate 3 a, and is blown from the air blow-out ports 32formed on the face panel 30 to the room to be air-conditioned). Asdescribed above, the thermal insulating member is disposed on the baseplate 3 a, and the air passing through the air filtering unit 4downwardly flows in the space between the thermal insulating member andthe air filtering unit 4, so that the temperature variation of the airin the filtering unit 3 can be suppressed to the minimum level.

FIGS. 4A and 4B are diagrams showing the construction of the main partof the filtering unit 3. FIG. 4A shows the outlook of the air filteringunit 4, and FIG. 4B is a diagram showing the construction of theelectrolytic water supply unit 5.

FIG. 5 is a diagram showing the construction of the filtering unit 3. InFIG. 5, the indoor heat exchanger 21, the drain pan 24 and the drainpump 27 are illustrated for convenience of understanding, and a part ofthe filtering unit 3 is schematically illustrated. In FIG. 5, thedirection indicated by an arrow G corresponds to the downward direction.

As shown in FIG. 4A, the air filtering unit 4 is equipped with agas-liquid contact member (humidifying element) 41 having high waterretentivity, and a water dispersing tray 42 disposed on the gas-liquidcontact member 41 at the installation state of the indoor unit (FIG. 2).The gas-liquid contact member 41 is formed of non-woven cloth formed ofacrylic fiber, polyester fiber or the like. A raw material having littlereactivity to electrolytic water is preferably used as the raw materialof the gas-liquid contact member 41, and further not only the aboveacrylic fiber, the polyester fiber, etc., but also other materials suchas polyolefin-based resin (polyethylene resin, polypropylene resin orthe like), vinyl chloride resin, fluorinated rein (PTFE, PFA, ETFE orthe like), cellulose-based material, ceramics-based material, etc. maybe used. The gas-liquid contact member 41 may be subjected to ahydrophilic treatment or the like to enhance the affinity of thegas-liquid contact member 41 to electrolytic water. Accordingly, thewater retentivity (wettability) of the gas-liquid contact member 41 toelectrolytic water is kept, and the air introduced to the gas-liquidcontact member 41 can be surely brought into contact with electrolyticwater.

The water dispersing tray 42 drops electrolytic water supplied from theelectrolytic water supply unit 5 through an electrolytic water injectiontube 51 to the gas-liquid contact member 41. A connection port 42 a towhich the electrolytic water injection tube 51 is connected is formed inthe side surface of the water dispersion tray 42. Furthermore, manyholes (not shown) through which electrolytic water is dropped anddispersed/infiltrated into the gas-liquid contact member 41 are formedin the bottom surface of the water dispersing tray 42. By droppingelectrolytic water form the water dispersing tray 42 to the gas-liquidcontact member 41, the electrolytic water is uniformly to the overallgas-liquid contact member 41.

The electrolytic water supplied to the gas-liquid contact member 41 anddrops off the gas-liquid contact member 41 is stocked in an electrolyticwater tray 43 described later.

The electrolytic water injection tube 51 introduces the electrolyticwater generated in the electrolytic water supply unit 5 to the waterdispersing tray 42.

As shown in FIG. 4B, the electrolytic water supply unit 5 has anelectrolytic bath 52 supplied with water such as tap water or the likefrom an external water supply source. At least a pair of electrodes 53a, 53 b are disposed in the electrolytic bath 52, and a voltage isapplied to the electrodes 53 a and 53 b to electrolyze water and thusgenerate electrolytic water containing active oxygen species.

Here, the active oxygen species means oxygen molecules having higheroxidizing activity than normal oxygen and also related substancethereof, and contain not only so-called narrowly-defined active oxygensuch as superoxide anion, singlet oxygen, hydroxyl radical and hydrogenperoxide, but also so-called broadly-defined active oxygen such asozone, hypohalous acid (hypochlorous acid, etc.), etc.

As described above, the electrolytic bath 52 is fixed to one face of thebase plate 3 a and proximate to the gas-liquid contact member 41disposed at the opposite surface of the base plate 3 a, so thatelectrolytic water containing active oxygen species can be immediatelysupplied to the gas-liquid contact member 41 through the electrolyticwater injection tube 51.

The electrodes 53 a, 53 b are two electrode plates each of which isconstructed by a base of titan (Ti) and a coating layer of iridium (Ir),platinum (Pt), for example.

By applying a voltage between the electrodes 53 a and 53 b, hydrogenions (H⁺) and hydroxide ions (OH⁻) in water react with each other at acathode according to the following reaction formula (1):

4H⁺+4e⁻+(4OH⁻)→2H₂+(4OH⁻)   (1)

Furthermore, water is electrolyzed at an anode according to thefollowing reaction formula (2):

2H₂O→4H⁺+O₂+4e⁻  (2)

At the same time, chlorine ions (chloride ions; Cl⁻) contained in waterreacts according to the following reaction formula (3), and chlorine(Cl₂) is generated.

2Cl⁻→Cl₂+2e⁻  (3)

Furthermore, Cl₂ thus generated reacts with water according to thereaction formula (4), and hypochlorous acid (HCLO) and hydrogen chloride(HCL) occur:

Cl₂+H₂O→HClO+HCl   (4)

The active oxygen species such as hypochlorous acid (HCLO) having strongsterilization power or the like is generated by supplying currentbetween the electrodes 53 a, 53 b, and electrolytic water containingthis active oxygen species is supplied to the gas-liquid contact member41. By passing air through the gas-liquid contact member 41 under theabove state, virus, etc. floating in the air passing through thegas-liquid contact member 41 concerned are inactivated and thus the aircan be filtered. In addition, breeding of various bacterial, fungus,etc. in the gas-liquid contact member 41 itself can be prevented.

Gaseous materials which are causative agents of odor, etc. in the airare dissolved in the electrolytic water or react with active oxygenspecies such as hypochlorous acid or the like contained in theelectrolytic water, whereby these materials are removed from the airwhen passing through the gas-liquid contact member 41, so that the aircan be also deodorized by the gas-liquid contact member 41.

Furthermore, when current having a predetermined current density (forexample, 20 mA/cm² or the like) is supplied between the electrodes 53 a,53 b, electrolytic water containing active oxygen species having apredetermined concentration (for example, free residual chlorineconcentration of 1 mg/l or the like) can be generated by electrolysis ofwater. Furthermore, by changing the current value, the concentration ofthe active oxygen species in the electrolytic water can be changed. As aspecific example, when the current value is reduced, the concentrationof hypochlorous acid of electrolytic acid can be reduced. On the otherhand, when the current value is increased, the concentration of thehypochlorous acid of the electrolytic water can be increased.

In this embodiment, a water (tap water or the like) adjusting portion 6including a connecting pipe 50, a water (tap water or the like) controlvalve 46 and a check valve 47 may be connected to the upstream side ofthe electrolytic water supply unit 5 as shown in FIG. 5.

FIG. 5 is a systematic diagram showing the flow of electrolytic waterpassing through the air filtering unit. In FIG. 5, the directionindicated by an arrow G corresponds to the downward direction.

The check valve 47 is connected to a water (tap water or the like)introduction pipe (water supply pipe) 48 through a connector 59. Thewater (tap water or the like) control valve 46 is disposed at thedownstream side of the check valve 47. The opening/closing state and theopening degree of the water control valve 46 is adjusted under thecontrol of an electrical component board 40 described later. Theconnecting pipe 50 intercommunicating with the water control valve 46extends to the electrolytic water supply unit 5, and the electrolyticwater supply unit 5 is supplied with water whose amount corresponds tothe opening degree of the water control valve.

The water (tap water or the like) introduction pipe 48 extends to theneighborhood of the housing 20 along the joint pipe 35 and the drainpipe 27 a passing through the cut-out potion 20 f, and connects to theelectrolytic water supply unit 5. Therefore, when the indoor unit 2 isinstalled while embedded in the ceiling, the connection work of thewater introduction pipe 48, the joint pipe 35, the drain pipe 27 a, etc.can be collectively performed , so that the labor required for theinstallation can be reduced.

Here, a water supply source which is located at the upstream side of thewater (tap water or the like) introduction pipe 48 to supply water maybe city water (tap water) or water stocked in a water supply tank or thelike. Furthermore, the water stocked in the water supply tank or thelike may be water containing ion species such as chloride ions or thelike in advance like tap water or the like, or water containing a rareamount of ion species such as well water or the like. In the firstembodiment, these kinds of water are collectively called as ”water”.

As shown in FIG. 5, the electrolytic water tray (water receiving tray)43 is disposed below the gas-liquid contact member 41. The electrolyticwater supplied from the water dispersing tray 42 to the gas-liquidcontact member 41 drops from the gas-liquid contact member 41 to theelectrolytic water tray 43, and the drop electrolytic water is stockedin the electrolytic water tray 43. The drain pipe 44 for guiding thestocked electrolytic water to the drain pan 24 is connected to thebottom surface of the electrolytic water tray 43. Both the ends of theelectrolytic water tray 43 are mounted and fixed to the base plate 3 aby the fixing tags 61 as shown in FIG. 2. As not shown, the gas-liquidcontact member 41 is joined to the electrolytic water tray 43 by a stay(not shown) or the like, and supported by the base plate 3 a.

The electrolytic water supplied from the electrolytic water supply unit5 to the air filtering unit 4 is stocked in the electrolytic water tray43. A suction nozzle 49A of the circulating pump 49 is disposed in theelectrolytic water tray 43, and electrolytic water stocked in theelectrolytic water tray 43 is pumped up by the circulating pump 49, andsupplied to the electrolytic water supply unit 5 through the connectingpipe 50.

The drain pipe 44 connected to the lower portion of the electrolyticwater tray 43 is equipped with a flow rate (or amount) control valve 45as an electromagnetic valve, the flow rate control valve 45 isopened/closed or the opening degree thereof is adjusted under thecontrol of the electrical component board 40 described later, andelectrolytic water stocked in the electrolytic water tray 43 flows outto the drain pipe 44 in accordance with the opening degree of the flowrate control valve 45. The drain pipe 44 is opened above the drain pan24, and the electrolytic water flowing out to the drain pipe 44 dropsoff to the drain pan 24. Accordingly, the electrolytic water stocked inthe electrolytic water tray 43 is discharged in accordance with theopening degree of the flow rate control valve 45.

Furthermore, the electrolytic water tray 43 is provided with a flowswitch 54 for detecting the water level of the stocked electrolyticwater. The float switch 54 is connected to the electrical componentboard 40. When a low water level is detected by the float switch 54,that is, it is detected by the float switch 54 that the water level inthe electrolytic water tray 43 is lower than a predetermined water levelrequired to circulate electrolytic water, the electrical component board40 opens the tap control valve 46 to supply tap water or the like to theelectrolytic water supply unit 5.

The electrical component board 40 is equipped with CPU (not shown), ROMfor storing a control program executed by CPU, control data associatedwith the control program, etc., and RAM for temporarily storing programsand various kinds of data which are processed by CPU, etc. CPU performsvarious kinds of control such as the current supply control for theelectrodes 53 a, 53 b in the electrolytic water supply unit 5, theopening degree control of the flow rate control valve 45, the openingdegree control of the water control valve 46, the driving control of thecirculating pump 49, etc. according to the control program in ROM. Forexample, in order to generate electrolytic water of a predeterminedconcentration in the electrolytic water supply unit 5, CPU makes currentflow between the electrodes 53 a and 53 b at the current densitycorresponding to the concentration concerned. Furthermore, in order tosupply water from the water introduction pipe 48 to the electrolyticwater supply unit 5, CPU adjusts the opening degree of the water controlvalve 46 and adjusts the opening degree of the flow rate control valve45 to discharge the electrolytic water stocked in the electrolytic watertray 43. Furthermore, CPU drives the circulating pump 49 to circulateelectrolytic water in the electrolytic water supply unit 5 and the airfiltering unit 4.

Furthermore, CPU of the electrical component board 40 is connected toCPU of the controller 8 through a communication line or the like (notshown), and executes the above control according to an instruction inputfrom the controller 8, for example, an instruction input in the remotecontroller. Accordingly, electrolytic water can be supplied to the airfiltering unit 4 interlockingly with the cooling/heating operation ofthe outdoor unit 1 or independently of the cooling/heating operation ofthe outdoor unit 1.

Next, the operation of the air conditioner 100 according to the firstembodiment will be described.

When an instruction of starting the operation is input through theremote controller (not shown) by a user, the controller 8 executes theoperation based on the instructed operation mode (cooling operationmode/heating operation mode) and switches the four-way valve 13 of theoutdoor unit 1 to the cooling side or the heating side to perform apredetermined air-conditioning operation such as cooling operation,heating, operation or the like as shown in FIG. 1.

When the cooling operation is carried out, the controller 8 switches thefour-way valve 13 to the cooling side so that refrigerant flows in therefrigerant circuit 100 a as indicated by a broken-line arrow of FIG. 1,the outdoor heat exchanger 14 functions as a condenser and the indoorheat exchanger 21 functions as an evaporator. Then, the controller 8operates the air blowing fan 22 to suck an indoor air from the airsuction pot 31, heat-exchanges the indoor air in the indoor heatexchanger 21 and supplies the cooled air to the air filtering unit 4 inthe indoor unit 2. The air supplied to the air filtering unit 4 is blownout from the air blow-out ports 32 to a room to be air-conditioned.

When the heating operation is carried out, the controller 8 switches thefour-way valve 13 to the heating side so that the refrigerant flows inthe refrigerant circuit 100 a as indicated by a solid-line arrow of FIG.1, the outdoor heat exchanger 14 functions as an evaporator and theindoor heat exchanger 21 functions as a condenser. Then, the controller8 operates the air blowing fan 22 to suck the indoor air from the airsuction port 31, heat-exchanges the indoor air in the indoor heatexchanger 21 and supplies the heated (warm) air to the air filteringunit 4 (see FIG. 5). The air supplied to the air filtering unit 4 isblown out from the air blow-out pots 32 to the room to beair-conditioned.

Furthermore, at the same time when the air-conditioning operation iscarried out, the controller 8 outputs an instruction to the electricalcomponent board 40, and the air filtering operation is carried out underthe control of the electrical component board 40. That is, theelectrical component board 40 opens the water control valve 46 to supplywater (tap water or the like) to the electrolytic water supply unit 5,and makes the electrolytic water supply unit 5 to electrolyze water,generate electrolytic water containing active oxygen species such ashypochlorous acid or the like and supply the generated electrolyticwater to the air filtering unit 4. Furthermore, the electrical componentboard 40 drives the circulating pump 49 to circulatively supply theelectrolytic water to the air filtering unit 4.

Through the air filtering operation, the air passing through the indoorheat exchanger 21 is brought into contact with the electrolytic watercontaining the active oxygen species on and in the gas-liquid contactmember (element) 41 to thereby filter the air.

As described above, according to the first embodiment, in the indoorunit 2 of the in-ceiling embedded type air conditioner 100, air passingthrough the indoor heat exchanger 21 is passed through the gas-liquidcontact member 41 into which electrolytic water infiltrates, so thatvirus, etc. contained in the air whose temperature is adjusted bycooling or heating can be inactivated or removed. Accordingly, the airconditioner 100 can be brought with the air filtering function, and itcan simultaneously or individually implement both the air conditioningfunction and the air filtering function with no restriction ininstallation space, that is, the indoor unit and the air filtering unitcan be assembled into one body. Furthermore, the air conditioner canalso implement the air filtering function with no restriction ininstallation space on the floor surface of the room to beair-conditioned.

Furthermore, the opening portion 20 d is formed in the side plate 20 aconstituting the side surface of the housing 20, and the air filteringunit 4 is inserted through the opening portion 20 d into the housing 20,so that the air filtering unit 4 can be easily assembled to the indoorunit 2.

Furthermore, in the indoor unit 2, the electrolytic water supply unit 5is disposed at the outside of the housing 20 and thus the air flowpassage is not narrowed by the existence of the electrolytic watersupply unit 5. Therefore, it does not induce unfavorable matters such asincrease of air flow resistance or the like, and the space in thehousing 20 can be effectively used. In addition, the maintenance of theelectrolytic water supply unit 5 can be easily performed.

The filtering unit 3 is constructed by fixing the gas-liquid contactmember 41 to one surface of the base plate 3 a and also providing theelectrolytic water supply unit 5 for generating electrolytic water, etc.to the other surface of the base plate 3 a. Therefore, by fixing thebase plate 3 a to the side plate 20 a, the air filtering unit 4 and theelectrolytic water supply unit 5 can be easily secured to each other.Furthermore, the gas-liquid contact member 41 and the electrolytic watersupply unit 5 are proximate to each other, and thus generatedelectrolytic water can be quickly supplied to the gas-liquid contactmember 41.

In the first embodiment, the drain pump 27 is disposed at one corner ofthe housing 20, and the air filtering unit 4 is disposed along the sideplate 20 a adjacent to the locating position of the drain pump 27.Therefore, electrolytic water discharged to the drain pan 24 quicklyreaches the drain pump and also it is quickly discharged to the outsideof the indoor unit 2. Accordingly, the electrolytic water does not stayin the drain pan 24 for a long time, and thus the effect of theelectrolytic water on the indoor heat exchanger 21 can be suppressed tothe minimum level. Accordingly, for example, when an anticorrosivetreatment is conducted on the indoor heat exchanger 21, the treatmentarea can be minimized.

In the first embodiment, the electrical component board 40 supplies theelectrolytic water stocked in the electrolytic water tray 43 to theelectrolytic water supply unit 5 by driving the circulating pump 49 evenwhen the water control valve 46 is closed and the water supply from thewater introduction pipe 48 is stopped. Accordingly, even when theelectrolytic water supply unit 5 is stopped, electrolytic water issupplied to the air filtering unit 4, and also water can be efficientlyused, so that the use amount of water can be saved. Furthermore, whenthe amount of circulating electrolytic water is reduced due tovaporization or the like, the low water level is detected by the floatswitch 54, so that the water control valve 46 is opened under thecontrol of the electrical component board 40 to supply fresh water tothe electrolytic water supply unit 5.

Electrolytic water stocked in the electrolytic water tray 43 passesthrough the drain pipe 44 and drops to the drain pan 24 by opening theflow rate control valve 45 under the control of the electrical componentboard 40. Here, the electrical component board 40 can drops electrolyticwater stocked in the electrolytic water tray 43 to the drain pan 24intermittently (for example, every hour or the like) or at all times onthe basis of user's selection. The electrolytic water dropped to thedrain pan 24 is discharged to the outside together with the drain waterstocked in the drain pan 24 by the drain pump 27.

Accordingly, the electrolytic water circulated in the air filtering unit4 and the electrolytic water supply unit 5 is periodically replaced byfresh water, and for example scales accumulated on the electrodes 53 a,53 b of the electrolytic water supply unit 5 can be discharged. Inaddition, electrolytic water containing active oxygen species havingsterilizing power flows into the drain pan 24, and thus breeding ofvarious bacteria, etc. in the drain pan 24 can be effectivelysuppressed, so that cleanness can be kept in the drain pan.

Furthermore, in the first embodiment, one filtering unit 3 is secured tothe indoor unit 2. However, another air filtering unit 3 may be easilyadded to the indoor unit 2. That is, each of the three side plates 20 aconstituting the housing 20 has the knock-out hole portion 20 c, andfiltering units 3 can be provided to all the three knock-out holeportions 20 c. That is, three filtering units 3 may be assembled to theindoor unit of the first embodiment. This construction will be describedhereunder as a second embodiment.

Second Embodiment

In the second embodiment, as shown in FIG. 6, the knock-out holeportions 20 c of the confronting two side plates 20 a are punched out toform opening portions 20 d, and the filtering units 3 are disposed atthe thus-formed two opening portions 20 d. These filtering units 3 aredesigned to have the same construction as the filtering unit 3 describedabove. That is, each of the two filtering units 3 has a plate portion 3a which is fit to the opening portion 20 d to close the opening 20 d,and the air filtering unit 4 is secured to the inner surface of theplate portion 3 a through fixing tags 61. The air filtering unit 4 issecured through the fixing tags 61, and thus a gap is provided betweeneach air filtering unit 4 and the plate portion 3 a. A thermalinsulating member of foamed polystyrene is provided to the side surfaceof the inner surface of the plate portion 3 a. On the other hand, theelectrolytic water supply unit 5 described later, the water (tap wateror the like) control valve, the check valve 47, the circulating pump 49,the electrical component board (controller) 40, etc are secured to theoutside of the plate portion 3 a. The outside of the filtering unit 3 iscovered by the exterior cover 80.

According to the construction of the second embodiment, a larger rate ofair to be blown out from the indoor unit 2 to the room to beair-conditioned can be filtered and thus the air filtering capability ofthe indoor unit 2 can be greatly enhanced.

As described above, the knock-out hole portions whose number correspondsto the required air filtering capability are punched out, and then thefiltering units 3 whose numbers corresponds to the number of thepunch-out knock-out hole portions are fitted to the indoor units throughthe knock-out hole portions, that is, the number of the filtering units3 to be fitted to the indoor unit 2 is changed in accordance with therequired filtering capability, thereby implementing the filteringcapability which is conformed with the condition of the room to beair-conditioned. Accordingly, for example in a hospital, a school or aplace which an unspecified number of persons enter and leave, a largernumber of (for example, three) filtering units 3 are secured to theindoor unit 2 to implement higher air filtering capability. On the otherhand, when the hermetically-sealed condition of a room is relativelyhigh and thus a sufficient effect can be achieved with low air filteringcapability, a smaller number of (for example, one) filtering unit 3 issecured to the indoor unit 2. The adjustment of the air filteringcapability as described above can be easily implemented by a simple workof punching out the knock-out hole portion 20 c and securing thefiltering unit 3 to the indoor unit 2.

Third Embodiment

FIG. 7 is a cross-sectional view of the indoor unit having the airfiltering apparatus according to the third embodiment.

In the embodiment shown in FIG. 7, the electrolytic water supply unit 5is not fixed to the base plate 3 a unlike the first embodiment shown inFIG. 2. Therefore, the electrolytic water introducing tube 51 extendingfrom the electrolytic water supply unit 5 to the gas-liquid contactmember 4 is designed to upwardly project, downwardly turn once,penetrate through the base plate 3 a and then reach the gas-liquidcontact member 4. It is most preferable that the electrolytic watersupply unit 5 is fixed to the base plate 3 a as in the case of the firstembodiment. However, by properly turning the electrolytic waterintroducing tube 51, the electrolytic water supply unit 5 may bedisposed not to be fixed to the base plate 3 a.

Fourth Embodiment

Net, a fourth embodiment of the present invention will be described.

According to the fourth embodiment, the operation mode is controlled inthe constructions of the first to third embodiment. The air conditioner1 according to the fourth embodiment may be implemented by using anyconstruction of the first to third embodiments, however, theconstruction of the first embodiment shown in FIGS. 1 to 5 is used as apreferable example.

FIG. 8 is a block diagram showing the construction of the main part ofthe air conditioner according to the fourth embodiment.

The controller 8 stores the control program corresponding the operationmode of the air conditioner 100 and also controls the outdoor unit 1,the electrical component board 40, the air blowing fan 22, etc.

The controller 8 is supplied with various kinds of instructions from auser through a remote controller 36 for remote operation (hereinafterreferred to as ”remote controller”).

The controller 8 inputs various kinds of operation instructions to theelectrical component board 40, whereby the electrical component board 40controls the electrolytic water supply unit 5, the float switch 54, thewater (tap water or the like) control valve 46, the circulating pump 49,etc.

The float switch 54 detects the presence or absence of water in theelectrolytic water tray 43 by detecting whether the electrolytic watertray 43 contains electrolytic water whose water level is equal to apredetermined permissible water level or more. When a detection signalindicating no water is input from the float switch 54 to the electricalcomponent board 40, the electrical component board 40 opens the watercontrol valve 46 and supplies tap water or the like to the electrolyticwater unit until the presence of water is detected.

The remote controller 36 generates an instruction signal in accordancewith a user's operation, and transmits the instruction signal to thecontroller 8. The remote controller 36 is equipped with at least anair-conditioning button 37 and an air filtering button (switchingoperation unit) 38.

The air-conditioning button 37 is a button for instructing an operationassociated with the operation state of the indoor unit 2 by the user.The controller 8 controls the air-conditioning operation of the indoorunit 2 in response to the operation of this air-conditioning button 37.

FIG. 9 is a state transition diagram of the operation mode of the airconditioner.

The air-conditioning operation based on the indoor unit 2 and the airfiltering operation based on the filtering unit 3 are interlocked witheach other. For example, when the air-conditioning button 37 is operatedunder the state that the air-conditioning operation is stopped, theoperation mode is shifted to an interlocking operation mode of executingthe air-conditioning operation and the air filtering operation at thesame time.

When the air-conditioning button 37 is operated under the state that theair-conditioning operation of the indoor unit 2 is executed, theoperation mode is shifted to an operation stop mode of stopping both theair-conditioning operation and the air filtering operation.

The air filtering button 38 instructs (start/stop of) the air filteringoperation of the filtering unit 3 by user's operation.

When the air filtering button 38 is operated under the state that theair conditioner 100 operates in the interlocking operation mode in whichthe air-conditioning operation based on the indoor unit 2 and the airfiltering operation based on the filtering unit 3 are executed, theinterlocking operation mode is shifted to an independentair-conditioning operation mode in which only the air-conditioningoperation is executed.

When the air filtering button 38 is operated under the state that theair conditioner 100 operates in the independent air-conditioning mode inwhich only the air-conditioning operation is executed by the indoor unit2, the independent operation mode is shifted to the interlockingoperation mode of executing both the air-conditioning operation and theair filtering operation.

When the air filtering button 38 is operated under the state that theair conditioner 100 stops both the air-conditioning operation and theair filtering operation in an operation stop mode, the indoor unit 2 ismade to execute the air blowing operation based on the air blowing fan22, and the operation stop mode is shifted to an independent airfiltering operation mode of executing only the air filtering operationbased on the filtering unit 3.

When the air filtering button 38 is operated under the state that theair conditioner 100 operates in the independent air filtering operationmode of executing only the air filtering operation based on thefiltering unit 3 without air conditioning operation, the independent airfiltering operation mode is shifted to the operation stop mode.

FIG. 10 is a flowchart showing the operation of the indoor unit 2 whenthe remote controller is operated.

When the air conditioner 100 is powered on, the controller 8 judgeswhether the remote controller 36 is operated or not (step S1).

If it is judged in step S1 that the remote controller 36 is not operated(step S1: No), the controller 8 repeats the processing of the step S1until the remote controller 36 is operated.

On the other hand, if it is judged in step S1 that the remote controller36 is operated (step S1: Yes), the controller 8 judges whether theair-conditioning button 37 is operated or not (step S2).

If it is judged in step S2 that the air-conditioning button 37 isoperated (step S2: Yes), the controller 8 judges whether the airconditioner 100 is under air conditioning operation (step S3).

If it is judged in step S3 that the air conditioner 10 is underair-conditioning operation (step S3: Yes), the controller 8 shifts theoperation mode to the interlocking operation mode or the independentair-conditioning operation mode to the operation stop mode to stop theair-conditioning operation and the air filtering operation (step S5).

On the other hand, if it is judged in step S3 that the air conditioner100 is not under air-conditioning operation (step S3: No), thecontroller 8 shifts the operation mode of the air conditioner 100 fromthe independent air filtering operation mode or the operation stop modeto the interlocking operation mode, and executes the air-conditioningoperation and the air filtering operation (step S4).

If the air-conditioning button 37 is not operated in step S2 (step S2:No), the controller 8 judges whether the air filtering button 38 of theremote controller 36 is operated or not (step S6)

If it is judged in step S6 that the air filtering button 38 is notoperated, that is, a button other than the air-conditioning button 37and the air filtering button 38 is operated (step S6: No), thecontroller 8 executes the processing corresponding to the operatedbutton concerned (step S7), and finishes a series of processing when theremote controller 36 is operated.

On the other hand, if it is judged in step S6 that the air filteringbutton 38 is operated (step S6: Yes), the controller 8 judges whetherthe air conditioner 100 is under air-conditioning operation (step S8).

If it is judged in step S8 that the air conditioner is underair-conditioning operation (step S8: Yes), the controller 8 judgeswhether the air conditioner 100 is under air filtering operation (stepS9).

If it is judged in step S9 that the air conditioner 100 is not under airfiltering operation (step S9: No), the controller 8 shifts the operationmode of the air conditioner 100 from the independent air-conditioningoperation mode to the interlocking operation mode and executes both theair-conditioning operation and the air filtering operation (step S1).

If it is judged in step S9 that the air conditioner 100 is under airfiltering operation (step S9: Yes), the controller 8 shifts theoperation mode of the air conditioner 100 from the interlockingoperation mode to the independent air-conditioning operation mode, andexecutes only the air-conditioning operation (step S10).

If the air conditioner 100 is not under air-conditioning operation instep S8 (step S8: No), it is judged whether the air conditioner 100 isunder air filtering operation (step S12).

If it is judged in step S12 that the air conditioner 100 is under airfiltering operation (step S12: Yes), the controller 8 shifts theoperation mode of the air conditioner 100 from the independent airfiltering operation mode to the operation stop mode, and stops the airfiltering operation (step S14).

On the other hand, if it is judged in step S12 that the air conditioner100 is not under air filtering operation (step S12: No), the controller8 shifts the operation mode of the air conditioner 100 from theoperation stop mode to the independent air filtering operation mode, andexecutes the air filtering operation without executing theair-conditioning operation (step S13).

Through the above processing, when the user operates theair-conditioning button 37, the controller 8 switches the interlockingoperation mode and the operation stop mode therebetween in accordancewith the operation. At this time, the air-conditioning operation basedon the indoor unit 2 and the air filtering operation based on thefiltering unit 3 are interlocked with each other, and thus the airfiltering operation can be executed interlockingly with theair-conditioning operation, or the air filtering operation can bestopped interlockingly with stop of the air-conditioning operation.

Furthermore, when the air filtering button 38 is operated under thestate that the air conditioner 100 is under air-conditioning operation,the controller 8 switches the interlocking operation mode and theindependent air-conditioning operation mode therebetween. Therefore, theexecution/stop of only the air filtering operation based on thefiltering unit 3 can be switched to each other under the state that theair-conditioning operation is maintained. More specifically, when theair filtering button 38 is operated under the interlocking operationmode, the mode is switched to the independent air-conditioning mode.When the air filtering button 38 is operated under the independentair-conditioning mode, the mode is switched to the interlockingoperation mode.

Furthermore, when the air filtering button 38 is operated under thestate that the air conditioner 100 is not under air-conditioningoperation, the controller 8 switches the operation stop mode and theindependent air filtering operation mode therebetween, and thus theexecution/stop of the air filtering operation based on the filteringunit 3 can be switched to each other without executing theair-conditioning operation. More specifically, when the air filteringbutton 38 is operated under the operation stop mode, the mode is shiftedto the independent air filtering operation mode, and the air blowingoperation based on the air blowing fan and the air filtering operationbased on the filtering unit 3 are executed. When the air filteringbutton 38 is operated under the independent air filtering operationmode, the mode can be switched to the operation stop mode.

According to the fourth embodiment, the air conditioner 100 is providedwith the interlocking operation mode in which the air-conditioningoperation based on the indoor unit 2 and the air filtering operationbased on the filtering unit 3 are interlocked with each other.Accordingly, if the user merely pushes the air-conditioning button 37 ofthe remote controller 36 only once, the operation mode of the airconditioner 100 is shifted to the interlocking operation mode and theair-conditioning operation is executed. Furthermore, interlockingly withthe air-conditioning operation, the air filtering operation based on thefiltering unit 3 is executed. Therefore, it is unnecessary to executeplural operations, and both the air-conditioning operation and the airfiltering operation can be executed by only one operation, so that theoperationality can be enhanced.

Furthermore, the air conditioner 100 is provided with the independentair filtering operation mode in which only the air filtering operationbased on the filtering unit 3 is executed. Accordingly, if the usermerely pushes the air filtering button 38 only once when the airconditioner 100 is not under air-conditioning operation, the operationstop mode is switched to the independent air filtering operation mode,the air blowing operation based on the air blowing fan 22 of the indoorunit 2 is executed, and also the air filtering operation based on thefiltering unit 3 is executed. Therefore, it is unnecessary to executeplural operations, and the operation mode can be shifted to theindependent air filtering operation mode by only one operation, so thatthe operationality can be enhanced.

Still furthermore, when the operation mode is shifted to the independentair filtering operation mode, it is unnecessary to provide a dedicatedair blowing fan for the filtering unit 3 because the air blowing fan 22of the indoor unit 22 is driven, so that the number of parts can bereduced.

Still furthermore, according to the fourth embodiment, the airconditioner 100 switches the interlocking operation mode and theindependent air-conditioning operation mode therebetween by operatingthe air filtering button 38 under air-conditioning operation. Therefore,under the state that the air-conditioning operation is maintained, theexecution and stop of only the air filtering operation based on thefiltering unit 3 can be switched therebetween.

The present invention is not limited to the above embodiments. In thefirst to fourth embodiments, hypochlorous acid is generated as theactive oxygen species. However, ozone (O₃) and hydrogen peroxide (H₂O₂)may be generated as the active oxygen species. In this case, whenplatinum tantalum electrodes are used as the electrodes 53 a, 53 b,active oxygen species can be highly efficiently generated from evenion-species rare water by electrolysis.

That is, by supplying current between the electrodes 53 a, 53 b, thereactions indicated by the following reaction formulas (5) to (7) occursat the anode, and ozone is generated.

2H₂O→4H⁺+O₂+4e⁻  (5)

3H₂O→O₃+6H⁺+6e⁻  (6)

2H₂O→O₃+4H⁺+4e⁻  (7)

Furthermore, at the cathode, the reactions indicated by the followingreaction formulas (8) and (9) occur, and O₂ ⁻ generated by the electrodereaction and H⁺ in the solution are coupled to each other to generatehydrogen peroxide (H₂O₂).

4H⁺+4e⁻+(4OH⁻)→2H₂+(4OH⁻)   (8)

O₂ ⁻+e⁻+2H⁺→H₂O₂   (9)

In the construction of this embodiment, by making the current flowbetween the electrodes 53 a, 53 b, ozone and hydrogen peroxide havingstrong sterilizing power are generated, and electrolytic watercontaining ozone and hydrogen peroxide can be made. The concentration ofozone or hydrogen peroxide in the generated electrolytic water isadjusted to a concentration optimal to in activate target virus, etc.,and air is passed through the gas-liquid contact member 41 supplied tothe electrolytic water of the concentration concerned, whereby thetarget virus, etc. floating in the air can be inactivated. Furthermore,when gaseous materials such as odor, etc. are passed through thegas-liquid contact member 41, they are dissolved in the electrolyticwater or react with ozone or hydrogen peroxide in the electrolytic waterto be removed from the air, whereby the air can be deodorized.

In the indoor unit 2, the same reactions can be also induced even whenion-species rare water (pure water, purified water, well water, somekinds of tap water or the like) are used. That is, if a halogen compound(salt or the like) is added to ion-species rare water, the samereactions as (3) and (4) occur, and the active oxygen species can beachieved. That is, the air filtering apparatus 1 is not limited to tapwater containing a sufficient amount of chloride compound, and even whenother water is used, a sufficient air cleaning effect (inactivation,sterilization, deodorization, etc. of virus, etc.) can be exercised.

In this case, water introduced into the electrolytic bath 52 maybesupplied with chemical compounds (for example, halide or the like). Forexample, a chemical compound supply device for supplying the abovechemical compound may be provided in the indoor unit 2. This chemicalcompound supply device may be designed to inject a chemical compound onthe passage from the water (tap water or the like) introducing pipe 48to the electrolytic bath 52, or directly inject the chemical compoundinto the electrolytic bath 52, or supply the concentration-adjustedchemical compound from the water (tap water or the like) introducingpipe 48 into the indoor unit 2.

Here, salt or brine may be used as the chemical compound. For example,if the concentration of brine in the electrolytic bath 52 is adjusted to2 to 3% (weight percentage), electrolytic water containing hypochlorousacid or hydrogen peroxide (0.5% to 1%) can be generated by electrolyzingbrine in the electrolytic bath 52. According to this construction, evenwhen ion species in water introduced into the electrolytic bath 52 israre, the amount of the ion species can be increased by adding salt orbrine, whereby active oxygen species can be generated stably and highlyefficiently in the electrolysis process of water.

Furthermore, in each of the above embodiments, the four-way blow-out andin-ceiling embedded type air conditioner is used as an example of theair conditioner. However, the present invention is not limited to thistype, and the present invention may be applied to a one-way or two-wayair conditioner, or a non-in-ceiling embedded type such as awall-suspended type air conditioner or the like.

Still furthermore, in each of the embodiments, electrolytic waterpassing through the air filtering unit 4 is circulated and reused byproviding the circulating pump 49. However, the present invention is notlimited to these embodiments, and the electrolytic water passing throughthe air filtering unit 4 may be directly discharged without circulatingand reusing the electrolytic water by the circulating pump 49.

In the fourth embodiment, the independent air-conditioning operationmode and the interlocking operation mode are switched therebetween, andthe operating button for switching the execution and stop of the airfiltering operation under the air-conditioning operation, and the airfiltering button 38 is set as a common button serving as the operatingbutton for switching the independent air filtering operation mode andthe operation stop mode therebetween and executing the independentoperation/stop of the air filtering operation based on the filteringunit 3 under non-air-conditioning operation. However, the presentinvention is not limited to this style, and these operation buttons maybe provided as individual modes to the remote controller 36.

In the construction of each of the above-described embodiments, thematerial constituting the drain pan 24 and the detailed constructionsuch as the shape, etc. of the indoor heat exchanger 21 may bearbitrarily changed.

1. An indoor unit of an in-ceiling embedded type air conditionerincluding an air blower and an indoor heat exchanger accommodated in ahousing a substantially box-shape, comprising: a filtering unitincluding a gas-liquid contact member that is disposed at the downstreamside of the indoor heat exchanger on an air blowing passage throughwhich air sucked by the air blower flows in the indoor unit andinfiltrated with electrolytic water generated by electrolyzing water,the air and the electrolytic water being brought into contact with eachother in the gas-liquid contact member to filter the air.
 2. The indoorunit according to claim 1, wherein the housing has an opening portion atat least a part of the side surface thereof and the gas-liquid contactmember is inserted from the opening portion into the housing.
 3. Theindoor unit according to claim 2, wherein the filtering unit furthercomprises a plate-shaped member covering the opening portion, and anelectrolytic bath for generating the electrolytic water, and theelectrolytic bath is fixed to one surface of the plate-shaped member,and the gas-liquid contact member is fixed to the other surface of theplate-shaped member.
 4. The indoor unit according to claim 3, whereinthe filtering unit further comprises a water supply pipe that isdisposed along a refrigerant pipe connected to the indoor heat exchangerand supplies water to the electrolytic bath.
 5. The indoor unitaccording to claim 1, wherein the filtering unit further comprises anelectrolytic bath that is disposed at the outside of the housing andgenerates the electrolytic water.
 6. The indoor unit according to claim5, wherein the filtering unit further comprises a water supply pipe thatis disposed along a refrigerant pipe connected to the indoor heatexchanger and supplies water to the electrolytic bath.
 7. The indoorunit according to claim 1, wherein the filtering unit comprises a drainpan that is disposed below the indoor heat exchanger and receives drainwater from the indoor heat exchanger, a drain pump for discharging drainwater from the drain pan, an electrolytic water supply unit forsupplying the electrolytic water to the gas-liquid contact member fromthe upper side thereof so that the electrolytic water infiltrates thegas-liquid contact member, an electrolytic water tray that is disposedbelow the gas-liquid contact member and receives electrolytic waterdropped from the gas-liquid contact member, and a discharge pipe fordischarging electrolytic water stocked in the electrolytic water tray tothe drain pan.
 8. The indoor unit according to claim 7, wherein thedrain pump is disposed at one corner of the housing, and the gas-liquidcontact member is disposed along the side surface of the housing so asto be adjacent to the locating position of the drain pump.
 9. The indoorunit according to claim 7, wherein the filtering unit further comprisesa circulating and supplying unit for circulating and supplyingelectrolytic water stocked in the electrolytic water tray to thegas-liquid contact member.
 10. An air conditioner including an outdoorunit having a compressor and an outdoor heat exchanger, and an indoorunit having an air blower and an indoor heat exchanger, the outdoor unitand the indoor unit being connected to each other through a joint pipe,comprising: an air filtering apparatus including a gas-liquid contactmember that is disposed on an air flowing passage formed by the airblower of the indoor unit and infiltrated with electrolytic watercontaining active oxygen species so that air passing through thegas-liquid contact member is brought into contact with the electrolyticwater to filter the air; and a controller for controlling the airconditioner having the air filtering apparatus, and selectivelyexecuting, as an operation mode, an interlocking operation mode forinterlocking an air-conditioning operation based on the air conditionerand an air filtering operation based on the air filtering apparatus, andan independent air filtering operation mode for executing only the airfiltering operation based on the air filtering apparatus withoutexecuting the air-conditioning operation based on the air conditioner.11. The air conditioner according to claim 1, further comprising aswitching operation unit for instructing switching of the operationmode, wherein according to an instruction from the switching operationunit, the controller shifts the operation mode to any one mode of anindependent air-conditioning mode for stopping the air filteringoperation based on the air filtering apparatus during execution of theinterlocking operation mode and executing the air-conditioningoperation, and the interlocking operation mode for starting the airfiltering operation based on the air filtering apparatus duringexecution of the independent air-conditioning mode and executing boththe air-conditioning operation and the air filtering operation.
 12. Theair conditioner according to claim 1, wherein the controller controlsthe indoor unit to execute air blowing operation based on the air blowerin the independent air filtering mode.
 13. A method of controlling anair conditioner including an outdoor unit having a compressor and anoutdoor heat exchanger, an indoor unit having an air blower and anindoor heat exchanger, and an air filtering apparatus including agas-liquid contact member that is disposed on an air flowing passageformed by the air blower of the indoor unit and infiltrated withelectrolytic water containing active oxygen species so that air passingthrough the gas-liquid contact member is brought into contact with theelectrolytic water to filter the air, the air conditioner having the airfiltering apparatus being operated in each of operation modes includingan interlocking operation mode for interlocking an air-conditioningoperation based on the air conditioner and an air filtering operationbased on the air filtering apparatus, and an independent air filteringoperation mode for executing only the air filtering operation based onthe air filtering apparatus without executing the air-conditioningoperation based on the air conditioner, comprising: a step of detectingan instruction of starting the air-conditioning operation or the airfiltering operation; a step of judging whether the air conditioner isnow under operation or under non-operation; and a step of starting theinterlocking operation mode when an instruction of starting theair-conditioning operation is detected and it is also judged that theair conditioner is now under non-operation, and starting the independentair filtering operation mode when an instruction of starting the airfiltering operation is detected and the air conditioner is now undernon-operation.